Nakano Note (Nakano wa Kangaeru noda) NK 3912 198P/ODAS
The following improved orbital elements, by S. Nakano, are from 192 observations 1998 to 2018, including planetary perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas, Vesta, and non-gravitational effect of style II. The mean residual is +/- 0.59 arc second. Residuals for re-observations were -34" for Right Ascension and -6" for Declination from the prediction by T. Kobayashi in NK 2887 (= HICQ 2018/2019) with the delta-T correction = +0.013 day. It is difficult to judge which observations in 2018 are bad or good. See the previous orbits in NK 844, NK 1595, NK 1596 and NK 2887. Epoch = 2018 Dec. 28.0 TT T = 2018 Dec. 13.91265 +/- 0.00312 (m.e.) TT Peri. = 69.26490 +/- 0.00263 Node = 358.31062 +/- 0.00222 (2000.0) Inc. = 1.33825 +/- 0.00005 q = 2.0059648 +/- 0.0000033 AU e = 0.4432358 +/- 0.0000007 a = 3.6028981 +/- 0.0000021 AU n' = 0.14412062 +/- 0.00000012 P = 6.839 +/- 0.0000059 years A1 = -2.739 +/- 0.199 A2 = +1.02504 +/- 0.00331 A3 = -2.14892 +/- 0.02913 T = 1998 July 20.93942 TT Epoch = 1998 July 6.0 TT Peri. = 68.73730 e = 0.4481013 Node = 358.89306 (2000.0) a = 3.5772459 AU Inc. = 1.35203 n'= 0.14567361 q = 1.9742774 AU P = 6.766 years T = 2005 May 3.25876 TT Epoch = 2005 Apr. 20.0 TT Peri. = 69.05856 e = 0.4472175 Node = 358.72058 (2000.0) a = 3.5834460 AU Inc. = 1.34864 n'= 0.14529570 q = 1.9808662 AU P = 6.783 years T = 2012 Feb. 15.79361 TT Epoch = 2012 Feb. 3.0 TT Peri. = 69.05764 e = 0.4449155 Node = 358.51308 (2000.0) a = 3.5969526 AU Inc. = 1.34167 n'= 0.14447809 q = 1.9966127 AU P = 6.822 years The predicted orbit for the 2025 return is as follows: T = 2025 Oct. 9.69528 TT Epoch = 2025 Oct. 12.0 TT Peri. = 69.40589 e = 0.4450114 Node = 358.13766 (2000.0) a = 3.5943996 AU Inc. = 1.33826 n'= 0.14463205 q = 1.9948507 AU P = 6.815 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 1998/ 981222 958 0.3+ 0.1- 990215 118 0.2- 0.4+ 981215 910 0.2+ 0.6- 981224 360 0.2- 0.0 990216 691 0.8- 0.3- 981215 910 0.3- 1.0- 981224 360 0.5- 0.4+ 990216 691 0.2- 0.2+ 981215 910 0.4+ 0.9- 981224 360 0.4+ 0.1- 990216 691 1.1- 0.0 981216 046 0.6- 0.1+ 981226 910 0.1- 0.4- 990216 615 0.4+ 0.7+ 981216 046 0.9- 0.8- 981227 958 (0.1- 3.9+) 990216 615 0.8+ 0.1- 981216 046 0.4+ 1.2- 981227 958 1.9- 0.4+ 990216 615 0.1- 0.3+ 981216 557 0.6- 0.6- 981227 402 0.3+ 0.2- 990216 615 0.3+ 0.4+ 981216 910 0.4+ 0.4- 981227 402 0.1+ 0.5- 990216 615 0.1- 0.3+ 981216 046 0.6- 1.4- 981227 402 0.6+ 0.0 990216 615 0.2- 0.1+ 981216 046 1.1- 1.6- 1999/ 990216 615 0.4- 0.3+ 981216 910 0.1+ 0.3- 990107 897 1.5- 1.6+ 990216 615 0.8- 0.9+ 981216 910 0.1- 0.6- 990107 897 0.2+ 1.3+ 990216 615 0.2+ 0.3+ 981216 910 0.2- 0.7- 990107 897 0.3- 1.5+ 990216 615 0.1+ 0.7+ 981216 910 0.5- 1.3- 990110 372 0.3- 1.2+ 990216 615 0.1- 0.7+ 981216 586 0.6+ 0.1+ 990113 693 0.5- 0.0 990216 615 0.6- 0.5+ 981216 910 0.2- 0.8- 990113 693 0.6- 0.0 990216 615 0.2- 0.4+ 981216 586 0.5+ 0.3+ 990113 693 0.4- 0.1- 990216 615 0.2- 0.3+ 981216 586 0.5+ 0.1+ 990114 910 1.0+ 0.0 990216 615 0.2+ 0.7+ 981216 586 0.7+ 0.3+ 990114 910 1.0+ 0.5- 990218 608 0.1+ 0.1+ 981216 586 0.5+ 0.1+ 990114 910 0.4- 0.9- 990218 608 0.1+ 0.3- 981216 586 0.3+ 0.1+ 990115 910 0.2+ 0.9- 990218 608 0.7+ 0.8- 981216 586 0.2+ 0.3+ 990115 910 0.7+ 0.8- 990223 897 (1.2+ 2.9+) 981216 586 0.3+ 0.3+ 990115 910 0.8+ 1.3- 990223 897 (3.2+ 0.1+) 981216 586 0.7+ 0.3+ 990115 910 0.0 1.5- 990223 897 0.5+ 0.6- 981216 586 0.6+ 0.2+ 990115 910 0.3+ 1.4- 990316 402 0.2- 0.5+ 981216 586 0.4+ 0.3+ 990115 910 0.1- 0.6- 990316 402 (0.4- 2.2-) 981216 586 0.5+ 0.4+ 990115 910 0.1- 1.1- 990316 402 1.9- 1.0- 981216 586 0.5+ 0.4+ 990119 910 0.3+ 0.4+ 990404 402 1.8- 0.1+ 981216 611 0.1+ 0.9- 990119 910 0.4+ 0.2+ 990404 402 0.1- 0.2- 981217 611 (2.7- 0.9-) 990119 910 0.5+ 0.0 990414 693 (2.3- 0.7-) 981217 586 0.6- 0.1+ 990119 910 0.3- 0.0 990414 693 (5.1- 0.6+) 981217 586 0.1+ 0.1+ 990119 910 0.2+ 0.2+ 2005/ 981217 046 1.0- 0.5- 990119 910 0.1+ 0.2+ 051007 G96 (1.4- 2.4-) 981217 586 0.2- 0.2- 990119 910 0.0 0.1+ 051007 G96 0.6- 1.9- 981217 046 0.9- 0.1+ 990119 910 0.2+ 0.3+ 051007 G96 0.8- 1.5- 981217 046 0.2+ 0.2- 990119 910 0.3+ 0.0 051007 G96 (1.1+ 2.2-) 981217 586 0.1- 0.1+ 990119 910 0.0 0.6+ 2006/ 981217 046 0.1+ 0.1- 990121 360 0.7+ 0.6- 060130 691 0.1- 0.3- 981217 046 0.6+ 0.2- 990121 360 0.6+ 0.2- 060130 691 0.4- 0.6- 981217 586 0.6- 0.0 990121 360 0.3+ 0.3- 060130 691 0.4- 0.6- 981217 586 0.3- 0.1+ 990126 402 (2.4+ 0.9+) 060207 691 0.4- 0.0 981217 586 0.6- 0.2+ 990126 360 0.4+ 0.2+ 060207 691 0.3- 0.2- 981217 586 0.4- 0.1+ 990126 360 0.1- 0.2- 060207 691 0.0 0.1- 981217 586 0.6- 0.2+ 990126 360 0.5+ 0.1- 060220 691 0.2+ 0.1- 981217 586 0.7- 0.0 990205 897 0.7+ 0.2+ 060220 691 0.0 0.1- 981217 586 0.2- 0.2+ 990205 897 0.5- 1.0- 060220 691 0.0 0.2+ 981217 586 0.1- 0.0 990206 402 0.4+ 0.6- 060224 691 0.3+ 0.3+ 981218 511 0.1+ 0.4+ 990206 402 0.9+ 0.1- 060224 691 0.3+ 0.1+ 981218 511 0.0 0.4+ 990206 402 1.3+ 0.6+ 060224 691 0.6+ 1.0- 981218 511 0.2- 0.1+ 990208 402 1.4+ 0.6- 060302 691 0.3- 0.0 981218 511 0.2- 0.2+ 990208 402 1.5+ 0.2- 060302 691 0.5+ 0.4+ 981218 511 0.2- 0.3+ 990208 402 1.4+ 0.5- 060302 691 0.4+ 0.3+ 981218 511 0.0 0.3+ 990212 699 0.6- 1.1+ 060323 G96 1.1- 0.3+ 981218 511 0.2- 0.3+ 990212 699 0.3- 0.3+ 060323 G96 0.5+ 0.3+ 981218 511 0.2- 0.5+ 990212 699 0.1- 0.2+ 060323 G96 1.1- 0.4+ 981218 511 0.2- 0.8- 990213 691 0.5- 0.1+ 060323 G96 0.5+ 0.4+ 981218 402 0.9- 0.4+ 990213 691 0.6- 0.0 060324 G96 0.1+ 0.2+ 981218 402 0.7- 0.1+ 990213 691 0.1+ 0.3+ 060324 G96 1.2+ 0.1+ 981218 402 0.2+ 0.0 990213 691 0.2- 0.0 060324 G96 0.4- 0.2+ 981218 402 0.5- 0.5+ 990213 691 0.7- 0.7+ 060324 G96 0.0 0.4+ 981219 897 0.9- 1.8- 990213 691 0.5- 0.3- 2011/ 981219 897 (3.3- 1.9-) 990213 691 0.8- 1.0+ 110730 958 0.0 0.1- 981219 372 1.0+ 2.0+ 990213 691 0.3- 0.0 110730 958 (1.7- 3.4-) 981219 372 0.6+ 1.6+ 990213 691 0.5+ 0.9+ 2018/ 981220 897 (3.7- 0.3-) 990214 693 0.1+ 0.0 181215 Z55 (6.6+ 2.8+) 981221 372 (2.5+ 0.4+) 990214 693 0.2+ 0.1- 181215 Z55 (7.6+ 3.2+) 981221 360 0.7+ 0.6+ 990214 693 0.2+ 0.1- 181215 Z55 (7.5+ 2.7+) 981221 360 0.5+ 0.1+ 990214 360 0.2+ 0.3- 181225 160 0.1- 0.7+ 981221 360 0.1- 0.3+ 990214 360 0.3+ 0.1- 181225 160 0.2- 0.7+ 981222 958 0.5+ 0.7+ 990214 360 0.1+ 0.5- 181225 160 0.2- 0.7+ 981222 958 0.9- 0.3+ 990215 118 0.2+ 0.1- ( ) -------- Rejected Obs.
Associate of the CBAT Syuichi Nakano 2019 Nov. 6